Unusual bladder outflow obstruction: case report.

Hydatid disease, the parasitic infestation caused by the cestode, echinococcus granulosus involves mainly the liver and the lungs though no organ is immune. Genito urinary involvement has been found mainly in the kidneys and rarely in other structures such as, bladder and epididymis. Isolated retrovesical location of the hydatid cyst is a very rare condition whose manifestations appears after a long course of the disease and are due to compression of bladder, causing the bladder out flow obstruction. Such rare case of bladder out flow obstruction is presented.